Probing for factors influencing exhaled breath drug testing in sports - pilot studies focusing on the tested individual's tobacco smoking habit and sex.

RATIONALE Exhaled Breath (EB) was found to be a promising matrix in the field of sports drug testing due to the non-invasive and non-intrusive sampling procedure, but significant interindividual variations regarding detected drug concentrations have been observed in previous studies. In order to investigate whether the detectability of doping agents in EB is affected by the sex or tobacco smoking, two administration studies were conducted with male and female smokers and non-smokers concerning the elimination of the beta blocker propranolol and the stimulant pseudoephedrine into EB. METHODS Following the administration of 40 mg propranolol or 30 mg pseudoephedrine, a total of 19 participants, including female and male non-smokers as well as female and male smokers, collected EB and Dried Blood Spot (DBS) samples over a period of 24 h. Respective analyte concentrations were determined using liquid chromatography and high-resolution tandem mass spectrometry and semi-quantitative assays were characterized with regard to selectivity, limit of detection and identification, precision, linearity, and carry-over. RESULTS Both propranolol and pseudoephedrine were identified in post-administration EB samples from female and male non-smokers as well as female and male smokers, and maximum detected drug levels ranged from 9 to 2847 pg/cartridge for propranolol and from 26 to 4805 pg/cartridge for pseudoephedrine. Corresponding DBS levels were in a range of 4-30 ng/mL for propranolol and 55-186 ng/mL for pseudoephedrine. CONCLUSIONS Neither the consumption of cigarettes nor the sex appear to represent decisive criteria as to the detectability of propranolol or pseudoephedrine in EB, but interindividual variations regarding the detected drug levels were observed among all studied population groups.